U.S. patent number 5,656,560 [Application Number 08/223,715] was granted by the patent office on 1997-08-12 for bronze-tinted or grey-tinted soda lime silicate glass.
This patent grant is currently assigned to Flachglas AG, Pilkington plc. Invention is credited to Ferdinand Klosel, Eberhard Stotzel, Brian Yale.
United States Patent |
5,656,560 |
Stotzel , et al. |
August 12, 1997 |
Bronze-tinted or grey-tinted soda lime silicate glass
Abstract
The invention relates to a bronze-tinted or grey-tinted soda
lime silicate glass, in particular for the manufacture of flat
glass by the casting process or by the float process, with a basic
composition for the soda lime silicate glass of: The invention
resides in the fact that it contains the following colorants
additives: ______________________________________ Fe.sub.2 O.sub.3
: 0-0.45 weight % V.sub.2 O.sub.5 : 0.0-0.5 weight % MnO.sub.2 :
0.5-2 weight % NiO: 0.0-0.05 weight % CuO: 0.0-0.1 weight % CoO:
0.0-0.008 weight % ______________________________________ the sum
of the weight percentages of the constituents forming the soda lime
silicate glass being 100.
Inventors: |
Stotzel; Eberhard (Schermbeck,
DE), Klosel; Ferdinand (Dorsten, DE), Yale;
Brian (Lancashire, GB2) |
Assignee: |
Pilkington plc (Merseyside,
GB3)
Flachglas AG (Furth, DE)
|
Family
ID: |
6484806 |
Appl.
No.: |
08/223,715 |
Filed: |
April 6, 1994 |
Foreign Application Priority Data
|
|
|
|
|
Apr 6, 1993 [DE] |
|
|
43 11 180.7 |
|
Current U.S.
Class: |
501/72; 501/70;
501/71 |
Current CPC
Class: |
C03C
3/087 (20130101); C03C 4/02 (20130101); C03C
3/078 (20130101) |
Current International
Class: |
C03C
3/076 (20060101); C03C 3/087 (20060101); C03C
4/00 (20060101); C03C 4/02 (20060101); C03C
003/078 () |
Field of
Search: |
;501/70,71,72 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
5023210 |
June 1991 |
Krumwiede et al. |
5204293 |
April 1993 |
Amundson et al. |
5364820 |
November 1994 |
Morimoto et al. |
|
Foreign Patent Documents
Primary Examiner: Group; Karl
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak &
Seas
Claims
We claim:
1. Bronze-tinted or grey-tinted soda lime silicate glass having a
basic composition for the soda lime silicate glass of:
SiO.sub.2 in an amount of 66-74 weight %;
Al.sub.2 O.sub.3 in an amount of 0-3 weight %;
TiO.sub.2 in an amount of 0-0.15 weight %;
CaO in an amount of 7-12 weight %;
MgO in an amount of 2-6 weight %;
Na.sub.2 O in an amount of 10-15 weight %;
K.sub.2 O in an amount of 0-3 weight %;
BaO in an amount of 0-0.04 weight %;
SO.sub.3 in an amount of 0.1-0.4 weight %;
and further containing one or more of the following colourant
additives:
Fe.sub.2 O.sub.3 in an amount of 0-0.45 weight %;
V.sub.2 O.sub.5 in an amount of 0-0.5 weight %;
MnO.sub.2 in an amount of 0.5-2 weight %;
NiO in an amount of 0-0.05 weight %;
CuO in an amount of 0-0.1 weight %;
CoO in an amount of 0-0.008 weight %;
wherein the sum of the weight percentages is 100.
2. Soda lime silicate glass in accordance with claim 1, wherein the
Fe.sub.2 O.sub.3 content is in the range of 0.14 to 0.25 weight
%.
3. Soda lime silicate glass in accordance with claim 1, wherein the
MnO.sub.2 content is in the range of 1.0 to 1.7 weight %.
4. Soda lime silicate glass in accordance with claim 1, consisting
essentially of:
and colourant additives as follows:
5. Soda lime silicate glass in accordance with claim 1, consisting
essentially of:
and colourant additives as follows:
6. Soda lime silicate glass in accordance with claim 1, consisting
essentially of:
and colourant additives as follows:
7. Soda lime silicate glass in accordance with claim 1, consisting
essentially of:
and colourant additives as follows:
8. Soda lime silicate glass in accordance with claim 1, consisting
essentially of:
and colourant additives as follows:
9. Soda lime silicate glass in accordance with claim 1, consisting
essentially of:
and colourant additives as follows:
Description
The invention concerns a bronze-tinted or grey-tinted soda lime
silicate glass, in particular for the manufacture of flat glass by
the casting process or by the float process, with a basic
composition for the soda lime silicate glass of:
______________________________________ SiO.sub.2 : 66-74 weight %
Al.sub.2 O.sub.3 : 0-3 weight % TiO.sub.2 : 0-0.15 weight % CaO:
7-12 weight % MgO: 2-6 weight % Na.sub.2 O: 10-15 weight % K.sub.2
O: 0-3 weight % BaO: 0-0.04 weight % SO.sub.3 : 0.1-0.4 weight %
______________________________________
In the case of the flat glass with bronze tinting or grey tinting
manufactured today which is used for buildings as well as for
vehicles, the tinting is customarily obtained by the addition of
small quantities of selenium and cobalt of the order of 10 to 50
ppm of selenium and 30 to 40 ppm of cobalt to a usual soda lime
silicate glass basic composition. Soda lime silicate glasses have,
dependent on their content of Fe.sub.2 O.sub.3 a yellow or green
colour predominance. As a result of the addition of selenium and
cobalt, a shift of the spectrum locus in the chromaticity diagram
takes place towards the bronze values with dominant wavelengths of
580 nm to 610 nm until the required spectral purity is achieved. A
bronze-tinted glass customary on the market (soda lime silicate
glass), whose colouration is due to percentages of selenium and
cobalt, has the following composition:
______________________________________ SiO.sub.2 : 70.09 weight %
Al.sub.2 O.sub.3 : 1.39 weight % TiO.sub.2 : 0.06 weight % CaO:
8.09 weight % MgO: 5.01 weight % Na.sub.2 O: 14.11 weight % K.sub.2
O: 0.65 weight % BaO: 0.02 weight % SO.sub.3 : 0.22 weight %
______________________________________
the following colourant additives being used:
______________________________________ Fe.sub.2 O.sub.3 : 0.35
weight % CoO: 0.004 weight % and Se: 0.005 weight %
______________________________________
With a thickness of 4 mm, this known bronze-tinted glass has a
transmission factor with standard light types A and D65 (DIN 5033)
of 55.8% and 53.9% respectively, with total solar radiation
(TE-CIE) of 57.8%. The transmission values for UV light are: for
the UVA content 16.6%, for the UVB content 0.0% and for UV total
radiation 15.8%.
The colour coordinates (achromatic, defined in DIN 5033) are stated
as X=56.4, Y=54.3, Z=45.3, and x=0.3616, y=0.3482, z=0.2901
respectively; in addition, L* was determined as 78.7, a* as 5.2, b*
as 9.6. The spectral purity is 13.0.
The coordinates x and y define the position of the spectrum locus
in the chromaticity diagram which is shown for the glass described
in FIG. 1. The spectrum locus is indicated by "*" and the white
point by "x". 585.9 nm was determined as the dominant wavelength
imparting the colour shade.
(The limits for the colour are for bronze tinting in the ranges of
x=0.3333 to 0.3800 and y=0.3333 to 0.3800; for grey tinting in the
ranges of x=0.3100 to 0.3600 and y=0.3100 to 0.3600).
For a variety of reasons, the use of selenium is not without its
problems. At the temperatures customary in glass melting, it
evaporates in proportions of up to 90 weight %. On account of the
toxicity of selenium, legislation has specified observance of the
maximum permissible emission levels. At present, the selenium
emission in Germany may not exceed 1 mg/m.sup.3 of waste gas. Thus,
efficient filter systems must be provided in the waste gas system
of the glass melting furnace.
For these reasons, compositions for selenium-free bronze-tinted or
grey-tinted have long been examined for their usability in
production plants for flat glass. These contain a manganese oxide
as principal colourant substance.
The basic glass composition as well as control of the cooling
process are important for colouration. For the invention, it is
only the intention to consider soda lime silicate glasses which are
fabricated to flat glass under the usual conditions, preferably by
the casting or the float process.
From JP-A 52-47 812, a colourless glass is known which can also
contain manganese in the form of MnO.sub.2 as an alternative to
selenium. The content of MnO.sub.2 shall in this case not exceed
0.08 weight %.
In GB-A 708,031, the reciprocal effect of colourant additives on
the tinting of a soda lime silicate glass is discussed. Here, 0.2
to 1.2 weight % of vanadium pentoxide (V.sub.2 O.sub.5) is employed
to provide ultraviolet absorption, and 0 to approximately 0.45
weight % of MnO.sub.2 and traces of iron (up to 0.1 weight %),
cobalt, chromium or copper are employed in order to obtain a
pink-tinted glass. The proportions of V.sub.2 O.sub.5 and MnO.sub.2
must be matched to one another, as they can affect the
colouration.
In Schmidt/Voss "The Raw Materials for Glass Production", 2nd
edition (1958), on page 287, a recipe is given for grey-tinted
glass (smoked glass) with 4 weight % of Mn.sub.2 O.sub.3, 2 weight
% of Fe.sub.2 O.sub.3, 1 weight % of NiO and 1 weight % of CuO. For
technical reasons, a composition of this type cannot be used for
flat glass production.
From U.S. Pat. No. 4,116,704, a grey-brown tinted glass for the
production of cooking vessels is known, where the following are
present as colourant additives: 0.001 to 0.116 weight % of CoO,
0.037 to 0.0055 weight % of NiO and 0.6 to 0.21 weight % of
MnO.sub.2. The basic glass, however, is a borosilicate glass.
JP-A 81-41 579 discloses an infrared-absorbent grey-tinted glass
with 0.1 to 0.2 weight % of Fe.sub.2 O.sub.3, 0.001 to 0.004 weight
% of CoO, 0.02 to 0.06 weight % of NiO and 0.01 to 0.5 weight % of
MnO in soda lime silicate glass with a considerably increased
proportion of K.sub.2 O which can be in the range of 2.5 to 11.25
weight %.
The recipes stated cannot be used with soda lime silicate glasses
of the class described at the beginning. Shifting the K.sub.2 O
content to values as stated in JP-A 81-41 579, presumably there to
increase the refractive index, or in accordance with GB-A 708,031
is not possible without undesirable effects on the glass
properties. In the case of flat glasses, the refining process
additionally only permits a narrow margin for the
oxidation/reduction state of the glass. Nor can the cooling process
be utilized as a free parameter for colour adjustment.
The purpose of the invention is to provide a bronze-tinted or a
grey-tinted soda lime silicate glass, where the use of selenium is
completely dispensed with as a colourant component, but where
cost-effective colourant additives are used, manufacture being
possible in a production plant as is customary for soda lime
silicate glass and its optical properties being the same as those
of bronze-tinted glasses or grey-tinted glasses containing selenium
which are customary on the market.
This problem is solved in the case of a soda lime silicate glass of
the class described at the beginning by the features of the
Characterizing Section of Patent Claim 1. Advantageous
configurations are the subject of the Subclaims.
According to the invention, it is provided that colourant additives
be present in the following proportions:
______________________________________ Fe.sub.2 O.sub.3 : 0-0.45
weight % V.sub.2 O.sub.5 : 0.0-0.5 weight % MnO.sub.2 : 0.5-2
weight % NiO: 0.0-0.05 weight % CuO: 0.0-0.1 weight % CoO:
0.0-0.008 weight % ______________________________________
the sum of the weight percentages of the constituents forming the
soda lime silicate glass being 100. Increasing the manganese
content over the known ranges makes it possible to achieve
colouration, even under redox conditions of the usual sulphate
refining in a flat glass melt. Even in the case of pronounced
oxidation of the melt due to nitrate addition, it has been found
that the high manganese addition is necessary as after refining,
only a low content of the manganese is colour-effective.
Preferably, the proportion of MnO.sub.2 to be added is between 1.0
and 1.7 weight %. It has been found advantageous to provide a
proportion of Fe.sub.2 O.sub.3 in the range of 0.14 to 0.25 weight
%.
The invention will be explained in detail below with the aid
examples and the enclosed drawings. These show:
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1: The position of the spectrum locus in the chromaticity
diagram achromatic for seleniumbronze-tinted cast glass customary
on the market with a thickness of 4 mm;
FIG. 2: The position of the spectrum locus in the chromaticity
diagram achromatic for soda lime silicate glass with thickness of 4
mm in accordance with Example 1;
FIG. 3: The position of the spectrum locus in the chromaticity
diagram achromatic for soda lime silicate glass with thickness of 4
mm in accordance with Example 2;
FIG. 4: The position of the spectrum locus in the chromaticity
diagram achromatic for soda lime silicate glass with a thickness of
4 mm in accordance with Example 3;
FIG. 5: The position of the spectrum locus in the chromaticity
diagram achromatic for soda lime silicate glass with a thickness of
4 mm in accordance with Example 4;
FIG. 6: The position of the spectrum locus in the chromaticity
diagram achromatic for soda lime silicate glass with a thickness of
4 mm in accordance with Example 5;
FIG. 7: The position of the spectrum locus in the chromaticity
diagram achromatic for soda lime silicate glass with a thickness of
4 mm in accordance with Example 6.
EXAMPLE 1
(Bronze-tinted soda lime silicate flat glass, manufactured by the
casting process or the float process)
A soda lime silicate glass whose basic composition incorporates the
following:
______________________________________ SiO.sub.2 : 71.91 weight %
Al.sub.2 O.sub.3 : 0.64 weight % TiO.sub.2 : 0.04 weight % CaO:
8.51 weight % MgO: 3.82 weight % Na.sub.2 O: 13.29 weight % K.sub.2
O: 0.18 weight % BaO: 0.01 weight % SO.sub.3 : 0.21 weight %
______________________________________
is provided with colourant additives as follows:
______________________________________ Fe.sub.2 O.sub.3 : 0.14
weight % MnO.sub.2 : 1.20 weight % NiO: 0.04 weight % CoO: 0.002
weight % ______________________________________
By employing 0.14 weight % of Fe.sub.2 O.sub.3 and an MnO.sub.2
content of 1.20 weight % which is considerably increased in
comparison with known glass compositions, as well as nickel, as
colourant additives, an Mn.sup.2+ /Mn.sup.+ ratio of 92/8 is
achieved even under the close redox conditions of the customary
sulphate refining of a melt for production of flat glass, where a
proportion of colourant Mn.sup.+ adequate for the desired
bronze-tinting of the glass is uniformly present in the glass.
With a thickness of 4 mm, this bronze-tinted glass has a
transmission factor with the standard light types A and D65 of
53.3% and 51.2% respectively, with total solar radiation (TE-CIE)
of 67.3%. The transmission values for UV light are for the UVA
content 38.6%, for the UVB content 0.0% and for the UV total
radiation 36.8%.
The colour coordinates (achromatic) are stated as being X=53.5,
Y=51.7, Z=40.0 and x=0.3587, y=0.3561, z=0.2752; in addition, L*
was determined as 77.1, a*=4.7, b*=13.2. The spectral purity is
17.6. The position of the spectrum locus in the chromaticity table
diagram is shown in FIG. 2 for the glass described above. The
spectrum locus is denoted by "*", the white point by "x". 57.5 nm
has been determined as the dominant wavelength providing the
tint.
EXAMPLE 2
(Bronze-tinted soda lime silicate flat glass, manufactured by the
casting process or the float process)
A soda lime silicate glass whose basic composition incorporates the
following:
______________________________________ SiO.sub.2 : 71.86 weight %
Al.sub.2 O.sub.3 : 0.64 weight % TiO.sub.2 : 0.04 weight % CaO:
8.51 weight % MgO: 3.82 weight % Na.sub.2 O: 13.29 weight % K.sub.2
O: 0.18 weight % BaO: 0.01 weight % SO.sub.3 : 0.21 weight %
______________________________________
is provided with colourant additives as follows:
______________________________________ Fe.sub.2 O.sub.3 : 0.14
weight % MnO.sub.2 : 1.22 weight % NiO: 0.04 weight % CuO: 0.04
weight % ______________________________________
With a thickness of 4 mm, this bronze-tinted glass has a
transmission factor with the standard light types A and D65 of
56.9% and 5.2% respectively, with total solar radiation (TE-CIE) of
65.4%. The transmission values for UV light are for the UVA content
35.8%, for the UVB content 0.0% and for the UV total radiation
34.1%.
The colour coordinates (achromatic) are stated as being X=56.4,
Y=55.6, Z=42.4 and x=0.3656, y=0.3600, z=0.2744; in addition, L*
was determined as 79.4, a*=2.1, b*=14.2. The spectral purity is
17.9. The position of the spectrum locus in the chromaticity table
diagram is shown in FIG. 3 for the glass described above. The
spectrum locus is denoted by "*", the white point by "x". 580.5 nm
has been determined as the dominant wavelength. The colour
coordinates (achromatic) which are desired for a bronze tint are
achieved in practice with this composition.
EXAMPLE 3
(Grey-tinted soda lime silicate flat glass, with increased
UV-absorption manufactured by the casting process or the float
process)
A soda lime silicate glass whose basic composition incorporates the
following:
______________________________________ SiO.sub.2 : 72.26 weight %
Al.sub.2 O.sub.3 : 0.64 weight % TiO.sub.2 : 0.04 weight % CaO:
8.51 weight % MgO: 3.82 weight % Na.sub.2 O: 13.29 weight % K.sub.2
O: 0.18 weight % BaO: 0.01 weight % SO.sub.3 : 0.21 weight %
______________________________________
is provided with colourant additives as follows:
______________________________________ Fe.sub.2 O.sub.3 : 0.17
weight % V.sub.2 O.sub.5 : 0.2 weight % MnO.sub.2 : 0.66 weight %
CoO: 0.0045 weight % ______________________________________
This glass additionally possesses UV-absorbent properties. With a
thickness of 4 mm, it has a transmission factor with the standard
light types A and D65 of 58.3% and 58.1% respectively, with total
solar radiation (TE-CIE) of 59.3%. The transmission values for UV
light are for the UVA content 4.0%, for the UVB content 0.0% and
for the UV total radiation 3.8%.
The colour coordinates (achromatic) are stated as being X=58.2,
Y=58.1, Z=56.6 and x=0.3365, y=0.3360, z=0.3275; in addition, L*
was determined as 80.8, a*=0.2, b*=1.4. The spectral purity is 1.8.
The position of the spectrum locus in the chromaticity table
diagram is shown in FIG. 4 for the glass described above. The
spectrum locus is denoted by "*", the white point by "x". 580.5 nm
has been determined as the dominant wavelength.
EXAMPLE 4
(Bronze-tinted soda lime silicate flat glass, with increased
UV-absorption manufactured by the casting process or the float
process)
A soda lime silicate glass whose basic composition incorporates the
following:
______________________________________ SiO.sub.2 : 72.21 weight %
Al.sub.2 O.sub.3 : 0.64 weight % TiO.sub.2 : 0.04 weight % CaO:
8.51 weight % MgO: 3.82 weight % Na.sub.2 O: 13.29 weight % K.sub.2
O: 0.18 weight % BaO: 0.01 weight % SO.sub.3 : 0.21 weight %
______________________________________
is provided with colourant additives as follows:
______________________________________ Fe.sub.2 O.sub.3 : 0.17
weight % V.sub.2 O.sub.5 : 0.2 weight % MnO.sub.2 : 0.71 weight %
CoO: 0.0035 weight % ______________________________________
This glass additionally possesses UV-absorbent properties. With a
thickness of 4 mm, it has a transmission factor with the standard
light types A and D65 of 52.3% and 51.4% respectively, with total
solar radiation (TE-CIE) of 60.6%. The transmission values for UV
light are for the UVA content 3.6%, for the UVB content 0.0% and
for the UV total radiation 3.5%.
The colour coordinates (achromatic) are stated as being X=52.7,
Y=51.6, Z=48.2 and x=0.3455, y=0.3386, z=0.3160; in addition, L*
was determined as 77.1, a*=2.7, b*=3.7. The spectral purity is 3.2.
The position of the spectrum locus in the chromaticity table
diagram is shown in FIG. 5 for the glass described above The
spectrum locus is denoted by "*", the white point by "x". 588.7 nm
has been determined as the dominant wavelength.
EXAMPLE 5
(Bronze-tinted soda lime silicate flat glass, manufactured by the
casting process)
A soda lime silicate glass whose basic composition incorporates the
following:
______________________________________ SiO.sub.2 : 68.66 weight %
Al.sub.2 O.sub.3 : 1.39 weight % TiO.sub.2 : 0.06 weight % CaO:
8.09 weight % MgO: 5.01 weight % Na.sub.2 O: 14.11 weight % K.sub.2
O: 0.65 weight % BaO: 0.02 weight % SO.sub.3 : 0.22 weight %
______________________________________
is provided with colourant additives as follows:
______________________________________ Fe.sub.2 O.sub.3 : 0.23
weight % MnO.sub.2 : 1.52 weight % NiO: 0.033 weight % CoO: 0.0022
weight % ______________________________________
With a thickness of 4 mm, this bronze-tinted glass has a
transmission factor with the standard light types A and D65 of
55.4% and 53.4% respectively, with total solar radiation (TE-CIE)
of 67.7%. The transmission values for UV light are for the UVA
content 24.4%, for the UVB content 0.0% and for the UV total
radiation 23.3%.
The colour coordinates (achromatic) are stated as being X=55.8,
Y=53.9, Z=42.5 and x=0.3668, y=0.3538, z=0.2794; in addition, L*
was determined as 78.4, a*=4.9, b*=12.3. The spectral purity is
16.3. The position of the spectrum locus in the chromaticity table
diagram is shown in FIG. 6 for the glass described above. The
spectrum locus is denoted by "*", the white point by "x". 584.1 nm
has been determined as the dominant wavelength.
EXAMPLE 6
(Bronze-tinted soda lime silicate flat glass, manufactured by the
casting process)
A soda lime silicate glass whose basic composition incorporates the
following:
______________________________________ SiO.sub.2 : 68.58 weight %
Al.sub.2 O.sub.3 : 1.39 weight % TiO.sub.2 : 0.06 weight % CaO:
8.09 weight % MgO: 5.01 weight % Na.sub.2 O: 14.11 weight % K.sub.2
O: 0.65 weight % BaO: 0.02 weight % SO.sub.3 : 0.22 weight %
______________________________________
is provided with colourant additives as follows:
______________________________________ Fe.sub.2 O.sub.3 : 0.23
weight % MnO.sub.2 : 1.61 weight % NiO: 0.027 weight % CoO: 0.0014
weight % ______________________________________
With a thickness of 4 mm, this bronze-tinted glass has a
transmission factor with the standard light types A and D65 of
51.1% and 48.6% respectively, with total solar radiation (TE-CIE)
of 66.7%. The transmission values for UV light are for the UVA
content 24.3%, for the UVB content 0.0% and for the UV total
radiation 23.2%.
The colour coordinates (achromatic) are stated as being X=52.3,
Y=49.2, Z=38.4 and x=0.3736, y=0.3518, z=0.2746; in addition, L*
was determined as 75.6, a*=8.0, b*=12.5. The spectral purity is
17.6. The position of the spectrum locus in the chromaticity table
diagram is shown in FIG. 7 for the glass described above. The
spectrum locus is denoted by "*", the white point by "x". 587.9 nm
has been determined as the dominant wavelength.
The Features of the Invention disclosed in the above Specification,
in the Drawing and in the Claims can be essential for
implementation of the Invention both individually and in any
combination.
* * * * *